Cuz those who "dare" get on a raft a usually middle class white who benefited from a premium education and elect to come to the US. This means that they've reneged on a promise to return service to the country in return for this education. Kinda like going to West Point , then bailing from military service...... You don't usually see Black Cubans on those raft...........usually well educated whites........The blacks excel in government, and in sports.